Add license under Apache 2.0.

Add copyright + license notice to all files.
Enhance scripts to work around / drop license text when composing
multiple file.
Drop historical EForth reference.
Bump version number.

circleforth/circle.fs

@@ -1,4 +1,19 @@
 #! /usr/bin/env gforth
+
+\ Copyright 2021 Bradley D. Nelson
+\
+\ Licensed under the Apache License, Version 2.0 (the "License");
+\ you may not use this file except in compliance with the License.
+\ You may obtain a copy of the License at
+\
+\     http://www.apache.org/licenses/LICENSE-2.0
+\
+\  Unless required by applicable law or agreed to in writing, software
+\  distributed under the License is distributed on an "AS IS" BASIS,
+\  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+\  See the License for the specific language governing permissions and
+\  limitations under the License.
+
 ( CircleForth )
 vocabulary circleforth   circleforth definitions
 
@@ -78,6 +93,7 @@ p: last   p: state
 ( Bootstrap )
 boot
 : (   41 parse drop drop ; immediate
+: \   10 parse drop drop ; immediate
 ( And now we have comments! )
 include compound.fs
 ok